Imagine a bomb dropped on London ....

[Workingman]

.... and the windows blowing out in Manchester, Leeds and Bristol.

That is how powerful the largest ever live tested nucler weapon, the Tsar Bomba, was.

The Russians have just declassified a video of the event.

Some of the statistics are incredible: 50 megatons - 3,000 times the power of the Hiroshima bomb; air-blast at 4km (2.4m); total destruction at ground zero in a radius of 35kn (21m); blast felt 900km away (560m): mushroom cloud 67km high (42m); radiation fallout still coming down two years later.

Now that really was a weapon of mass destruction.

I wonder what part it played in the US (supported by the West) wanting to get to the Moon, Reagan's strategic defence space missile programme (SDI), Skylab, the Shuttle, detente, the fall of the Soviet Union, and the start of the International Space Station programme.

History might view it as one of the most powerful drivers of peace between two superpowers.

[Kaz]

Woah!!

[Suff]

The immediate fireball of a 35mt bomb reaches 2.2km in air burst and lasts for 22 seconds. Quite a bang.

But in the end it was decided that 500kt was around the most viable strike weapon as you could strike multiple targets, maximising havoc, with a single rocket. You might feel the blast 1,000km away, but 10 500kt warheads landing on 10 different cities, over more than 1000 km, destroys more.

I'm sure that Russia worked that out themselves. 35mt weapons were designed to destroy places like the Cheyenne Mountain complex.

[Workingman]

As did the Yanks and NATO.

It did not take the geniuses on both sides long to work out that if they both only let off a handful of such weapons it was 'Goodnight Vienna' for life on Earth, hence the move to smaller multiple warhead weapons often on one delivery rocket and deployed simultaneously over a wide physical area. Peacemaker and Trident.

It is interesting to note that these 475-500kt warheads have the highest yield / mass ratio. and form the major stocks of the world's strategic nuclear arsenals. If there ever is a nuclear war, and it is a big IF, it will be a short sharp shock. Millions will die, obviously, but it will not be the mutually assured destruction (MAD) as would have been the case with the multi-megatonne bombs such as the Tsar Bomba.

It was a geopolitical weapon and it worked. We are actually a lot 'safer' now than if the escalation of the past had gone on unchecked by the various nuclear weapons treaties that followed the test.